This invention relates to a swaging tool for use in swaging hydraulic fittings and the like.
Swaged hydraulic fittings for use in connecting tubes in hydraulic systems have been used for many years, especially in the aircraft industry. The tubes are inserted into a fitting usually comprising a cylindrical sleeve, and then the fitting is swaged with a swaging tool to produce a fluid-tight connection between the tubes. During the swaging operation, the fitting is compressed radially inwardly by the swaging tool. This causes annular ridges on the outer surface of the fitting to be flattened and transferred to its inner surface. As a result, annular indentations are formed in the tube, attaching it securely to the fitting.
In certain types of swaging operations, access to the fitting to be swaged may be very limited. As a result, there has existed a need for a swaging tool that will accomplish the swaging operation, yet be compact enough to gain access to the fitting. One relatively compact prior swaging tool is disclosed in U.S. Pat. No. 3,848,451, comprising an upper die held within a yoke and a lower die connected to the tool by a die holder. The yoke is removed by loosening a knurled nut, allowing the yoke to be separated from the remainder of the tool for initial connection to the fitting to be swaged. Despite the advances provided by this prior tool in terms of its relatively compact nature and versatility, there still remain situations where the ability of the tool to swage a fitting becomes very difficult and, at times, not possible.
In addition to the need for a more compact tool, there are numerous problems generally associated with the swaging tools of the prior art. One of these problems is the possibility that, during connection of the tool to the fitting to be swaged, one of the dies may be in an improper, reverse orientation in relation to the other die. This can cause incomplete and, therefore, unreliable swaging. A similar problem may occur when the dies are initially assembled in the tool itself, both in the factory and during use in the field, where one of the dies may be installed in a reverse orientation to the other die. Fittings that have been incompletely or defectively swaged must be discarded and replaced with a new fitting, and sometimes new tubing. This results in increased costs in terms of materials and labor, as well as increased inefficiency and related drawbacks.
It also is known that the lower die in many of the existing tools has a tendency to rotate or wobble during swaging. When die rotation or wobble occurs, it can damage the tool and result in a defectively swaged fitting To date, no adequate means has been developed to effectively prevent this problem. Recognizing tool wear resulting from repeated use of the tool over time could enable the operator to repair or replace the tool in time to prevent wear-related swaging problems from occurring. However, as yet no reliable means has been recognized to indicate tool wear. Numerous other problems are associated with the swaging tools of the prior art.
Accordingly, there has existed a need for a swaging tool that is even more versatile and compact in size to handle the various swaging situations confronting the operator. Furthermore, there has existed a need for a swaging tool that prevents a reversal of orientation of the dies with respect to each other, that prevents die rotation and wobble, and that indicates tool wear as a result of prolonged use. The present invention satisfies these and other needs, and provides further related advantages.